Add code to compare children.

src/wasm_test/compare.rs

@@ -124,10 +124,10 @@ fn compare_json_value<'b, 's>(
     }
 }
 
-fn compare_ast_node<'b, 's, 'p>(
+fn compare_ast_node<'e, 's, 'w>(
     source: &'s str,
-    emacs: &'b Vec<Token<'s>>,
+    emacs: &'e Vec<Token<'s>>,
-    wasm: &serde_json::Map<String, serde_json::Value>,
+    wasm: &'w serde_json::Map<String, serde_json::Value>,
 ) -> Result<WasmDiffResult<'s>, Box<dyn std::error::Error>> {
     let mut result = WasmDiffResult::default();
     let mut emacs_list_iter = emacs.iter();
@@ -289,7 +289,25 @@ fn compare_ast_node<'b, 's, 'p>(
         result.children.push(layer);
     }
 
-    // TODO: compare children
+    {
+        // Compare children.
+        let mut layer = WasmDiffResult::default();
+        if let Some(wasm_iter) = wasm
+            .get("children")
+            .map(|children| children.as_array())
+            .flatten()
+            .map(|children| children.iter())
+        {
+            layer.extend(wasm_compare_list(source, emacs_list_iter, wasm_iter)?)?;
+        } else {
+            layer.extend(wasm_compare_list(
+                source,
+                emacs_list_iter,
+                std::iter::empty::<&serde_json::Value>(),
+            )?)?;
+        }
+        result.children.push(layer);
+    }
 
     Ok(result)
 }
@@ -350,6 +368,43 @@ pub(crate) fn wasm_get_emacs_standard_properties(
     })
 }
 
+fn wasm_compare_list<'e, 's: 'e, 'w, EI, WI>(
+    source: &'s str,
+    emacs: EI,
+    wasm: WI,
+) -> Result<WasmDiffResult<'s>, Box<dyn std::error::Error>>
+where
+    EI: Iterator<Item = &'e Token<'s>> + ExactSizeIterator,
+    WI: Iterator<Item = &'w serde_json::Value> + ExactSizeIterator,
+{
+    let emacs_length = emacs.len();
+    let wasm_length = wasm.len();
+    if emacs_length != wasm_length {
+        return Ok(WasmDiffResult {
+            status: vec![WasmDiffStatus::Bad(
+                format!(
+                    "Child length mismatch. Emacs=({emacs:?}) Wasm=({wasm:?}).",
+                    emacs = emacs_length,
+                    wasm = wasm_length
+                )
+                .into(),
+            )],
+            children: Vec::new(),
+            name: "".into(),
+        });
+    }
+
+    let mut child_status = Vec::with_capacity(emacs_length);
+    for (emacs_child, wasm_child) in emacs.zip(wasm) {
+        child_status.push(compare_json_value(wasm_child, source, emacs_child)?);
+    }
+    Ok(WasmDiffResult {
+        status: Vec::new(),
+        children: child_status,
+        name: "".into(),
+    })
+}
+
 // pub fn old_wasm_compare_document<'b, 's, 'p>(
 //     source: &'s str,
 //     emacs: &'b Token<'s>,